Pipeline inspection keeps energy flowing at Shell St Fergus

Challenge

The Shell St Fergus gas plant plays a strategically important role meeting the UK’s daily gas requirements. It receives gas transported from a variety of UK continental shelf and Norwegian pipelines and then processes the gas for supply to the national grid for power generation. Shell commissioned Fugro to carry out an integrity inspection of their pipelines running into the St Fergus gas plant.

This was a complex project, undertaken in challenging weather and metocean conditions during Covid-19 restrictions. The inspection included a nearshore survey in a busy commercial fishing zone and onshore surveys over environmentally sensitive terrain featuring steep-sided dunes and extensive burrows.

Solution

At Fugro, the well-being of our teams is just as important as a successful delivery, and even more so during a global pandemic. To that end, we implemented a comprehensive Covid-19 management plan that covered the whole of this project to safeguard the health of our staff, the public and our colleagues from Shell. The plan included PCR testing, self-isolation before joining a vessel, and social distancing measures. Thanks to these precautions, everyone remained healthy and we achieved zero cases of Covid-19 during the project.

Meticulous planning

Our pipeline inspection campaign combined a range of technical disciplines in challenging conditions, both onshore and nearshore. However, through meticulous planning and the local knowledge and experience of Shell and Fugro personnel, we completed our surveys within 6 weeks and provided detailed pipeline depth-of-burial assessments and cathodic protection evaluations in a safe and sustainable manner.

We knew from the outset that the onshore topographic survey would be challenging because of the environmentally sensitive, steep-sided dune systems and animal burrows around St Fergus, which made safe routes for access and egress difficult and required meticulous journey management planning from our land survey team.

Nearshore activities

Nearshore, we faced scheduling obstacles. The Covid-19 pandemic was disrupting the issuing of marine permits and impacting our scope of work for the acoustic pipeline inspection. However, thanks to regular and open communication between our teams and Shell, we minimised the delay to the project start date.

The trailing wire cathodic protection surveys were then performed nearshore and confirmed the effectiveness of the pipeline cathodic protection systems. These results, combined with multibeam bathymetry, sidescan sonar acoustic inspection and sub-bottom profiler depth-of-burial surveys, confirmed the physical condition of the pipelines and gave Shell a holistic overview of the pipeline asset integrity.

Open communications

We worked hard to maintain and enhance Shell’s strong relationship with local stakeholders throughout the course of the nearshore survey programme, which covered a busy commercial fishing area. Open communication, including socially distanced chats on the quayside, addressed the concerns and requirements of all parties and also resulted in a clear and flexible survey design that fulfilled Shell’s inspection requirements and minimised the impact on local fisheries.

Innovative highlight

Using our unique experience and proven techniques, we provided a complete, integrated solution for both the onshore and nearshore surveys that met the needs of Shell and local stakeholders, and minimised impact on the environment. Close cooperation with our various partners, along with a willingness to share lessons learned from similar projects, enabled us to execute the surveys without a hitch.

Impact

We delivered this complicated project on time and within budget, demonstrating safety leadership from the outset to complete our surveys with zero safety incidents, despite:

• Surveying during the Covid-19 restrictions

• Operating in an area of steep dunes and rabbit burrows

• Working nearshore in difficult weather and metocean conditions

Throughout the inspection campaign, we went the extra mile to keep the lines of communication open between our various project teams, third-party technical experts, client asset managers at the gas terminal, and a range of local stakeholders.